A former British general has told the war crimes trial of Slobodan Milosevic in The Hague that Belgrade significantly hindered the work of international monitors during the 1998-99 conflict in Kosovo.

Karol Drewienkiewicz was in Kosovo in 1998 as a deputy commander of the Kosovo Verification Mission (KVM), charged with monitoring Belgrade's truce with the rebels.

Government officials withheld documents or information requested by the mission on several occasions, he said, preventing it tracking a build-up of Yugoslav security forces during the truce that winter.

Mr Drewienkiewicz is one of several witnesses who have appeared at the trial in The Hague since the end of a three-week adjournment after Mr Milosevic contracted influenza.

His mission was rarely, if ever, given information about the timetable of movements of the security forces, he said, while the Yugoslav army and police appeared to boost their presence on the ground and their chain of command strengthened.

Mr Drewienkiewicz, whose observer mission was authorised by the Organisation for Security and Co-operation in Europe (OSCE), singled out the Yugoslav refusal to allow monitors to inspect the army barracks in Pristina.

The section of Mr Milosevic's trial relating to Kosovo is expected to carry on for several months, and more than 100 witnesses are expected to be called.

The ex-president faces charges relating to war crimes in Kosovo, Croatia and Bosnia.

Europe's biggest war crimes trial since the end of World War II began on 12 February, and is expected to last two years.

Mr Milosevic does not recognise the court and has declined to plead, leading judges to enter a plea of not guilty on his behalf.

But he has defended himself in court against the charges, which he rejects as false.